Account payment

I have an account with Ackermans and I made 2 payment in January does two payments are not appearing on their system and they've been calling me to pay the account ang when I inquire about those payments no one is willing to help me I have sent them proof of payment more than once all they do is to call me and tell me about my account that's is been handed over to the lawyers but they not tracking my payment that I have made am so angry because I can't keep on paying the account and my payments are not showing